Cx: Ow arn->hkg y+ £435 / €485 (pe)
Having looked for some decent Y+ flights I found the following from Stockholm (ARN) to Hong Kong (HKG) via LHR.
€485 one way potentially part of their go-east sale.
Bookable on the airline website, expedia or your chosen OTA. Appears to have good availability into 2018 (I booked some for Aug 2018). I had some difficulty getting some OTAs to price, unless I put in one way only.
Reasonable price for CX metal with their upgraded PE fleet.
Some similar reasonable deals with SAS ARN->HKG (Premium Economy) for £920 / €1300 return.
EDIT: Books into economy H for LHR leg and premium economy E for long haul.